This is War!

Someone came into the store yesterday talking on her cellphone. She wasn't speaking too loudly, but I could hear every word she said, and she was the only customer in the store. After about ten minutes, her conversation was driving me crazy, and I was also annoyed that she hadn't made eye contact or acknowledged my presence in any way. I've never done anything like this before, but I decided to try to bother her. I turned the music up . . . . then up again. It didn't seem to faze her at all. I made it very loud. Again, no response, she didn't even blink. I felt bad doing it, but I turned it up even louder. I don't think she had the faintest idea that this was war - but, there was one happy side effect - at least I couldn't hear her, and once I couldn't hear her, I could concentrate on other things. Postscript: she eventually put down the phone, and I turned down the music, and we spoke a bit!